It was a dark and stormy night. Four great minds, at the behest of a fifth, convened at Cambridge in 1949 to discuss artificial intelligence over a five-course dinner. Had geneticist J.B.S. Haldane, physicist Erwin Schrödinger, mathematician Alan Turing, and philosopher Ludwig Wittgenstein actually met that night in the rooms of Britain's science adviser C.P. Snow, they may have enacted the drama revealed in The Cambridge Quintet. This work of "scientific fiction" presents what could have been the dawn of the still-raging debate over the nature of intelligence and its reproduction in "metal, glass, and plastic".

John L. Casti's characterizations allow the reader to savour the meal and pleasantries as well as the heated arguments. His impatient, arrogant Wittgenstein betrays a frenzied frustration with the subject, sporadically attacking the very notion of artificial intelligence as impossible. Turing, quieter and yet more forceful, explains his then- new ideas with the certainty of a prophet waiting for the world to catch up with him. Haldane, Schrödinger, and Snow play the two off one another while bringing their own considerable intellects to the subject for the first time. Discussion ranges from the nature of thought to the role of language in the brain with arguments that are sophisticated but informal. Casti takes some anachronistic liberties, but these serve to remind us that, had they not both died in 1951, Wittgenstein and Turing would have made contributions of great significance to artificial intelligence theory. As the men finish their dinner, they have reached no conclusion or agreement. Like a fine meal, the satisfaction found in this book comes from its consumption, not its digestion.  Rob Lightner

Once again, Tom Clancy manages to add new twists to the alternate U.S. history he initiated in The Hunt for Red October. In The Sum of All Fears, the centre of conflict is that perpetual hot spot, the Middle East, where a nuclear weapon falls into the hands of terrorists just as peace finally seems possible. Clancy realistically paints an almost unthinkable scenariothe bomb is planted on American soil in the midst of an escalation in tension with the Soviet Union; the terrorists hope to rekindle cold war animosity and prevent reconciliation between Israelis and Palestinians.

Despite such a dramatic story line, Clancy doesn't neglect the individuals who drive his tale. Jack Ryan's problems are as much domestic as they are part of the international crisis that is the ostensible narrative: National Security Director Elizabeth Elliot has the president's ear, and she has convinced him that Ryan's ethics are questionable. She hints at marital infidelity and an insider-trading scandal. Of course, both accusations are false, but her arguments have enough evidence behind them (some photographs of an innocent embrace with a friend for example) to cause a strain in the Ryans' marriage and a flurry of media attention. While "Mr Clark" tracks the terrorists, he also provides some needed intelligence to heal the Ryan family.

The Sum of All Fears is the stuff of nightmares but contains enough verisimilitude to terrify sober minds. Ryan has developed into a complex protagonist, just as Clancy's writing has matured. Ryan is plagued by stress and self-doubts that test even his dauntless moral compass and make him a more interesting subject for readers' attention. Those fascinated by military hardware, from nuclear submarines to atomic weapons, will find almost enough here to start their own army. And Clancy's understanding of international politics seems chillingly correct. Patrick O'Kelley

Razio Yamata is one of Japan's most influential industrialists, and part of a relatively small cabal who exert tremendous authority in the Pacific Rim's economic powerhouse. He has devised a plan to cripple America's pre-eminent standing, humble the U.S. military and elevate Japan to a position of dominance on the world stage. Yamata's motivation lies in his desire to pay off a Debt of Honour to his parents and to the country he feels is responsible for their deaths: America. All he needs is a catalyst to set his plan in motion. When the faulty gas tank on one Tennessee family's car leads to their fiery death, an opportunistic U.S. congressman uses the occasion to rush a new trade law through the system. The law is designed to squeeze Japan economically. Instead, it provides Yamata with the leverage he needs to put his plan into action. As Yamata's plan begins to unfold, it becomes clear to the world that someone is launching a fully integrated operation against the United States. There's only one man to find out who the culprit is: Jack Ryan, the new president's National Security Advisor.

There are many ways of recapturing the sheer fun that science fiction could be back when it was not even a bit respectable, and the idea that Arthur C. Clarke would one day be Sir Arthur was more or less inconceivable. One of the best ways is to go back to a classic short story collection like this, with its bitterly ironic title story of archaeology and its misunderstandings, the classic "Breaking Strain" with its two spacemen struggling over supplies that will do for one, and "The Sentinel", the story that acted as the seed for the late Stanley Kubrick's collaboration with Clarke, 2001. Clarke always had a more delicate and poetic side, and this collection includes one of his finest stories in this vein "Second Dawn" in which telepathically gifted aliens without hands deal with the moral dilemmas of science. Many of the stories deal with a Space Age that never wasClarke was assuming that things would happen later than they did, but that more would follow quicker; this in itself gives the book charm as an add on to its considerable conceptual wit. Few short story collections are SF classics, but this is a major exception. Roz Kaveney

Originally The Fountains of Paradise was intended to be Arthur C. Clarke's last novel, before the author came out of "retirement" to pen 2010: Odyssey Two. It is also one of his best, and being set in a fictionalised version of Clarke's adopted home of Sri Lanka, one of his most personal. The story is based around the fantastical yet scientifically supportable idea of a "Space Elevator", a "tower" from the earth to geo-stationary orbit, 23 000 miles "high". The purpose is to make access to space routine, safe and cheap, and the 22nd century-set novel essentially follows Vannevar Morgan in his quest to complete this monumental project.

There are grand set-pieces worthy of the best adventure story, a generous scattering of fascinating speculations and observations and, of course, Clarke's famous eye for the epic vistas inherent in large-scale science fiction: Slowly his eyes adapted, and in the depths of the mirror a faint red glow began to burn, and spread, and consume the stars. It grew brighter and brighter and flowed beyond the limits of the mirror; now he could see directly, for it extended halfway down the sky. A cage of light, with flickering, moving bars, was descending upon the earth. As much the novel of a poet as that of a scientist, The Fountains of Paradise makes striking use of the sometimes haunting history of Sri Lanka, a device echoed by Kathleen Ann Goonan in her Hawaiian set novel, The Bones of Time. Anyone seriously interested in great science fiction should really have both these books in their collection. Gary S. Dalkin